In 2015, per-capita health care spending grew by 5.0% and overall health spending grew by 5.8%, according to a study by the Office of the Actuary at the Centers for Medicare & Medicaid Services (CMS) recently released as a Web First by Health Affairs.

The report concludes that 2015 expenditure growth was primarily the result of increased use and intensity of services as millions gained health coverage, as well as continued significant growth in spending for retail prescription drugs.

Spending on prescription drugs increased 9.0% in 2015, lower than the 12.4% growth in 2014, yet significantly higher compared to 2.3% growth in 2013. On a per-enrollee basis, overall spending increased by 4.5% for private health insurance, 1.7% for Medicare, and 3.8% for Medicaid.

"Our significant progress in reducing the nation's uninsured rate, while providing strong protections for Americans if they get sick, would not be possible without the Affordable Care Act," said CMS Acting Administrator Andy Slavitt, quoted in a press release. "As millions more Americans have obtained health insurance, per-person cost growth remains at historically modest levels."

The report noted that over a 2-year period, 20 million individuals either gained private health insurance coverage or enrolled in the Medicaid program, primarily as the result of the Affordable Care Act. The share of the population with health coverage increased from 86.0% in 2013 to 90.9% in 2015.

Health care spending grew 2.1 percentage points faster than the overall economy in 2015, resulting in a 0.4 percentage-point increase in the health spending share of gross domestic product (GDP) – from 17.4% in 2014 to 17.8% in 2015. In the decade prior to the passage of the Affordable Care Act (2000-2009), health care spending increased 2.8 percentage points faster than GDP, on an annual average basis.